1. Field of the Invention
This invention relates to press-fit electrical terminals such as press-fit pins for mounting in plated through holes in a printed circuit board. These terminals may be held in recesses in, say, plastic bodies to provide, for instance, edge card connectors. More particularly, the invention relates to such components having a generally H-shaped press-fit zone with compliant fins interconnected by a central web.
2. Description of the Prior Art
A number of designs of press-fit electrical terminals such as pins or connectors are well known in the industry. They have press-fit zones with compliant portions which deform when inserted within a plated through hole of a circuit board or a recess of a plastic housing. The deformed portions locate with the hole or recess and maintain the component rigidly therein.
U.S. Pat. No. 3,827,004 describes a press-fit circuit board pin where the press-fit zone is generally H-shaped. A central web of smooth, planar configuration connects four generally parallel compliant fins to so provide the H-shape. The zone is formed by swaging the pin between appropriate dies. The work hardening involved in forming the fins provides an improved compliancy thereto. The thus formed pins are gathered by an insertion tool and staked into the plated through holes.
Upon insertion within such a plated through hole, the fins deform somewhat in accordance with the shape of the hole.
An H-shaped geometry has the advantage of a relatively rigid central web which prevents excessive flexing of the pin tip after installation. The compliant fins will accommodate insertion into plated through holes of a range of dimensions. This is of advantage since it is difficult to ensure accurate manufacturing tolerances of such holes. Because of this variance in plated through hole dimensions, it is desirable that the manufacturing tolerances of dimensions of the press-fit zone of the pin be maintained as close as possible.
Other forms of press-fit pins are described in, for example, U.S. Pat. Nos. 3,824,554 and 4,057,315. U.S. Pat. No. 3,824,554 describes a press-fit pin having a generally H-shaped press-fit zone, but where the central web joining the fins has symmetrical, inwardly-curved and smooth opposed surfaces. U.S. Pat. No. 4,057,315 describes a press-fit pin in which the press-fit zone includes a plurality of deformed segments alternately spaced from each other in opposite quadrants along the length of the zone.